SDB(3)SDB(3)NAME
sdb_init, sdb_open, sdb_query, sdb_close - the Simple Database Library.
SYNOPSIS
#include <sdb.h>
void sdb_init();
char *sdb_open(char *url);
void sdb_close(char *id);
int sdb_query(char *url, char *query, int (*callback)(int, char **,
void *), void *closure);
DESCRIPTION
The SDB library allows applications to support multiple database man‐
agement systems with negligeable overhead, in terms of code as well as
system resources.
sdb_init() initializes the library and registers the database drivers.
It is not necessary to call sdb_init explicitly, since it will be done
automatically when needed.
sdb_open() opens a database connection that can be used for multiple
queries. This is optional; calling sdb_query directly will simply open
and close the connection for each query. sdb_open returns a connection
id which is used in place of the url in calls to sdb_query.
sdb_query() calls the callback once for each row returned. No rows does
not indicate an error condition. sdb_query returns the number of rows
or -1 for error. The callback takes three arguments, an integer indi‐
cating the number of columns in the result, an array of pointers to the
fields and a pointer to some arbitrary data that the callback might
need. Values are always returned as strings.
sdb_close() closes the database connection opened by sdb_open.
EXAMPLES
This minimal program runs queries from the command line.
#include <stdio.h>
#include <stdlib.h>
#include <sdb.h>
static int callback(int n, char **p, void *closure)
{
int i;
for (i = 0; i < n; i++) {
printf("%s\t", p[i]);
}
printf("0);
return 0;
}
int main(int argc, char **argv)
{
if (argc != 3) {
fprintf(stderr, "Usage: sdb_demo url query\n");
return EXIT_FAILURE;
}
sdb_query(argv[1], argv[2], callback, NULL);
return EXIT_SUCCESS;
}
This program can be used to authenticate Squid proxy users.
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sdb.h>
static int cb_db(int n, char **p, void *closure)
{
return 0;
}
int main(int argc, char **argv)
{
char *url, query[1024];
int n;
char buf[256];
char *user, *passwd, *p;
setbuf(stdout, NULL);
if (argc != 2) {
fprintf(stderr, "Usage: sdb_auth url\n");
exit(1);
}
url = argv[1];
while (fgets(buf, 256, stdin) != NULL) {
if ((p = strchr(buf, '\n')) != NULL)
*p = '\0'; /* strip \n */
if ((user = strtok(buf, " ")) == NULL) {
printf("ERR\n");
continue;
}
if ((passwd = strtok(NULL, "")) == NULL) {
printf("ERR\n");
continue;
}
sprintf(query,
"select * from htpasswd "
"where user = '%s' "
"and passwd = '%s'",
user, passwd);
n = sdb_query(url, query, cb_db, NULL);
if (n < 1) {
printf("ERR\n");
} else {
printf("OK\n");
}
}
exit(0);
}
SEE ALSO
sdbd.8
Example clients in sdb_client.c and sdbd_client.c.
AUTHOR
Copyright (c) 2000-2005 Ulric Eriksson <ulric@siag.nu>
This library is free software; you can redistribute it and/or modify it
under the terms of the GNU Library General Public License as published
by the Free Software Foundation; either version 2 of the Licence, or
(at your option) any later version.
This library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MER‐
CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library
General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.
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